import sys

class SimpleLogger:
    def __init__(self, log_file):
        self.log_file = log_file
        self.original_stdout = sys.stdout
        self.log_stream = None

    def start(self):
        self.log_stream = open(self.log_file, 'w', encoding='utf-8')
        sys.stdout = self.log_stream

    def stop(self):
        sys.stdout = self.original_stdout
        if self.log_stream:
            self.log_stream.close()